Ratchet mechanism



E. J. ARMSTRONG RATCHEJT MECHANI SM Original Filed 1919 5 Sheets-SheetAug. 31 1926..

RATCHE! MECHANI SM 3 Sheets-Shee t 2 Original Filed Oct 1919 Aug.31,1926. 1,598,412

E. J. ARMSTRONG RATCHET MECHANI SM Original Filed 1919 I5 Sheets-Sheet 3Patented Aug. 31, 192i.

UNITED STATES EDWIN J. ARMSTRONG,

PANY, OF ERIE,

1,593, t13 TENT @FFMIE.

RATCHET MECHANISM.

Original application filed October 30, 1919, Serial No. 334,515.

' February 26, 1923.

In many devices such as winding drums it is not only necessary to beable to wind the drum in a winding-up direction but it is also necessaryto control the unwinding of the drum under load. The present inventionis well designed for this purpose and accomplishes the same in a simpleand efficient manner. The structure here shown and claimed forms adivision oi application filed by me Oct. 30th, 1919 No. 334,515.

The invention is illustrated in the accompanying drawings as follows z-Fig. 1 shows a side elevation, partly in section, of the ratchetmechanism in position for winding a drum or reel.

Fig. 2 a similar view of the same mechanism, the parts being in positionfor unwinding the drum.

Fig. 3 a plan view the drum.

Fig. 4 a view similar to Fig. 2 except that the parts have been moved toa diil'erent position in the cycle of operation of unwinding the reel ordrum.

marks the reel. This is shaft 15 in supports 6. A ratchet wheel is fixedon the end of the reel 15. A pawl carrier 21 is mounted on the rod 15and a bracket 21 which extends from the strut 6. A pawl lever 22 ispivotally mounted on the carrier 21 by means of a pin 22. A link 23 ispivotally connected with the lever by means of a pin 24 and with anoperating lever 26 by means of a pin 25. The operating lever ispivotally mounted on a bracket 28 by means of a pin 27. A pawl 29 ispivotally mounted on the pawl lever 22 by means of a pin 30 and isadapted to operate against the teeth 31 on the ratchet wheel 20. Thepawl 29 thus forms the swinging pawl, A spring 32 pulls the pawl towardor into ongagement with the ratchet wheel. A pawl 33 is pivotallymounted on the pin 22, It, therefore, has a fixed pivotal support. Anarm 34 extends from this pawl and a spring 35 extends from the arm 34 toa part of the pawl carrier 21. The spring swings the pawl 33 intoengagement with the ratchet 20 so as to lock the ratchet againstunwinding as the pawl 29 is retracted after being advanced. By observingthe parts as shown in Fig. 1 the operation or" the step by stepmechanism for the winding up operation is made clear. As the operatinglever 26 is of the ratchet end of carried by a Divided and thisapplication filed Serial No. 621.338.

reciprocated the pawl lever 22 is reciprocated, reciprocating the pawl29 and thus advancing tooth by tooth the ratchet wheel 20, the ratchetwheel being caught and held against a return movement by the pawl 33.

In order that the step by step mechanism may be utilized for releasingthe support, that is, unwinding the reel under load it is provided withthe following mechanism: A disengaging finger orv dog 36 is provided onthe pin 22 and has an arm 37 from which extends a spring 38. The spring38 is carried by the lever 39, the lever being pivoted on a pin 40 inthe pawl carrier. The lever has an extension or arm 41 to which link 42is attached by a pin 43. The link 42 is connected by a pin 44 with anarm 45. Tie arm 45 is pivotally mounted by a pin 46 on the bracket 28. Alink 47 extends from the pin 44 to a grip lever 49 pivoted at 49, thelink being connected to this lever by means of a pin 48. When the griplever is swung to the position shown in Figs. 2 and 4 the pin 44 isbrought approximately to the center of the pin 27 so that the link 42remains stationary as the operating lever is operated.

The releasing mechanism operates as follows: It will be noted that asthe link 42 is pulled down through the grip lever 49, thespring 38 isput under tension. The spring 38 is stronger than the spring 35. Therelease dog 36 is under the influence ot the spring 38 and operatesagainst the pawl 33 so that when there are no other agencies in actionthe release dog operating under the influence of the spring 38 willovercome the spring 35 and move the pawl 33 out of: the path of theratchet, the position assumed under these conditions being shown in Fig.4.

The pawl 29 has a release finger 51 which extends into the path of therelease dog 36. The spring 38 with the leverages provided exerts apreponderance of pressure over the spring 32, or spring 35 as the casemay be, so that when the parts are not otherwise effected the spring 38will force thedog 29 through the dog 36 and release finger 51 to aposition which will clear the ratchet teeth 31 or the ratchet 20. Theposition of the parts under these conditions is clearly shown in Fig. 2.

The operation is as follows: Starting with enter the second notch abovethe pawl 33.

As it engages the tooth 31 and relieves the pressure of the ratchetwheel trom the pawl 33 the pawl is pushed outwardly by the dog to theposition shown in 4. The operating lever is then retracted allowing theratchet wheel to advance so as to unwind the reel and as the swingingpawl is retractci'l in this movement the pawl 33 slides along the innersurface of the pawl 29 into posi tion with the tooth next adjacent tothe tooth engaged by the pawl 29. As soon as the load is taken up by thepawl 33 a further movement of the pawl 29 releases this pawl so that itsnaps to the position shown in 2, the pawl 38 being locked in place byits engagement with the ratchet wheel under load. It will be noted thatthis is a single operating step by step mechanism and thus has anelement of safety in that it is practically impossible to so manipulatethe operating lever as to release one dog before the engagement of theother. This is very necessary in a device of this type because ot theheavy load and the danger of permitting it to fall.

What I claim as new is 1. In a ratchet mechanism, the combination of aratchet wheel; a fixedly mounted pawl; a swingingly mounted pawloperating on the ratchet wheel; a system comprising opposing springsoperating on said pawls; and means for changing the relative strength ofopposing springs for reversing the action of said pawls.

2. In a ratchet mechanism, the combination of a ratchet wheel; a fixedlymounted pawl operating on the ratchet wheel; a swingingly mounted pawloperating on the ratchet wheel; a spring operating on the fixedlymounted pawl; a spring operating on the swingingly mounted pawl; adisengaging finger acting on said pawls; a spring operating on thedisengaging finger; and

means independent of the disengaging finger for varying the tension ofsaid lastmentioned spring to reverse the action of the pawls.

3. In a ratchet mechanism, the combination of a ratchet wheel; a fixedlymounted pawl operating on the ratchet wheel; a swingingly mounted pawloperating on the ratchet wheel; a spring operating on the fixedlymounted pawl; a spring operating on the swingingly mounted pawl; adisengagipg finger operating alternately on pawls; av spring acting onsaid disengaging linger; and means for varying the tension of thelast-mentioned spring to vary the action of the pawls.

l. in a ratchet mechanism, the combination of a ratchet wheel; a fixedlymounted pawl; a spring acting on said pawl; a swingingly mounted pawl; aspring acting on said swingingly mounted pawl; a disengaging fingeroperating alternately on said pawls one of said pawls being guided intoengagement with the ratchet wheel by direct engagement with the other ofsaid pawls; a spring operating on the disengaging finger; and means forvarying the tension on the last-mentioned spring to vary the action of:the pawls.

5. In a ratchet mechanism, the combination of a ratchet wheel; a fixedlymounted pawl; a swingingly mounted pawl operating on the ratchet wheel;means for actuating the swingingly mounted pawl comprising a lever; asystem comprising opposing springs operating on said pawls; and meansfor changing the relative strength of said opposing springs forreversing the action of said pawls said means comprising a mechanism onsaid lever.

6. In a ratchet mechanism, the combination of a ratchet wheel; a fixedlymounted pawl; a swingingly mounted pawl operating on the ratchet wheel;means for actuating the swingingly mounted pawl comprising a lever; asystem comprising opposing springs operating on said pawls; and meansfor changing the relative strength of said opposing springs forreversing the action of said pawls, said means comprising a mechanismhaving a portion concentric with the pivot of the lever.

In testimony whereof I have hereunto set my hand.

EDlVIN J. ARMSTRONG.

